Xylooligosaccharides Enhance Lettuce Root Morphogenesis and Growth Dynamics

Area of Science:

• Agricultural Science
• Plant Biology
• Biotechnology

Background:

• Root development is crucial for crop yield and stress tolerance.
• Plant growth regulators like indole-3-butyric acid potassium salt (IBAP) are used to enhance root systems.
• Sustainable biostimulants are sought after in agriculture.

Purpose of the Study:

• To investigate the effects of xylooligosaccharides (XOSs) on lettuce root growth.
• To compare the efficacy of XOSs with IBAP in promoting root development.
• To elucidate the molecular mechanisms underlying XOS-induced root enhancement.

Main Methods:

• Lettuce plants were treated with XOSs and IBAP, with water as a control.
• Root growth parameters (dry weight, length, volume, surface area) were measured.
• Phytohormone levels were analyzed using comprehensive profiling.
• RNA sequencing (RNA-seq) was performed to identify differentially expressed genes (DEGs).

Main Results:

• XOS treatment significantly increased root dry weight, length, volume, and surface area, comparable to IBAP.
• XOS application elevated levels of indole-3-acetic acid (IAA), zeatin riboside (ZR), methyl jasmonate (JA-ME), and brassinosteroids (BRs).
• RNA-seq revealed 3807 DEGs in XOS-treated roots, enriched in pathways for manganese homeostasis, microtubule motor activity, and carbohydrate metabolism.
• XOS uniquely affected genes in cutin, suberine, wax biosynthesis, and plant hormone signal transduction.
• Upregulation of beta-glucosidase and beta-fructofuranosidase genes indicated enhanced carbohydrate metabolism.

Conclusions:

• Xylooligosaccharides (XOSs) are effective biostimulants that promote lettuce root growth and development.
• XOSs act through mechanisms involving phytohormone regulation and modulation of specific gene expression pathways.
• XOSs represent a promising sustainable alternative to synthetic plant growth regulators for improving crop productivity and resilience.